U.S. Pat. No. 4,199,545 discloses a chemical reactor capable of carrying out selected chemical reactions at extremely high temperatures. The reactor includes a reactor tube mounted in a generally vertical orientation. The reactor tube is made of a fabric of a fibrous refractory material capable of being heated to temperatures at which it emits intense radiant energy. The reactor also includes electrically resistive heating elements spaced about the reactor tube for heating a reaction zone spaced interiorly of the tube. A heat shield surrounds the heating elements and the reactor tube to reflect radiant energy toward the reaction zone.
In operation, reactants are dropped through the heated reaction zone of the reactor tube where they are heated to high temperatures by radiant energy emitted by the reactor tube. In order to prevent reactants and reaction products from engaging the interior wall of the reactor tube, a gas which is substantially transparent to radiant energy and preferably inert with respect to the tube material is passed through the pores of the fibrous tube to form a fluid wall for the inner surface of the reactor tube.
The '545 patent discloses inlet assemblies secured to the housing of the reactor for introducing liquid and solid reactants into the reaction zone of the reactor. The inlet assemblies include an inlet tube which extends into the reactor tube generally along an axis of the reactor tube. In the case of the inlet assembly for liquid reactants, a fogging nozzle is mounted on the end of the inlet tube.
The inlet assemblies for the reactor of the '545 patent have given rise to a number of significant problems. If the axis of the inlet tube is not correctly aligned with the axis of the reactor tube, feedstock discharged from the inlet tube may be directed toward the inner surface of the reactor tube with sufficient force to penetrate the fluid wall and engage the inner surface of the reactor tube. At the high temperatures at which the reactor operates, feedstock typically reacts with the reactor tube material, so that impingement of feedstock on the inner surface of reactor tube will corrode and destroy the reactor tube. In addition, feedstock may form deposits on the inner surface of the reactor tube, which may build up and restrict the flow of gas through the reactor tube, thereby further reducing the effectiveness of the fluid wall.
Misalignment of the inlet tube for the reactor disclosed in the '545 patent is difficult to avoid (because of component tolerances) and troublesome to correct. In order to change the alignment of the inlet tube relative to the reactor tube, the top section of the reactor housing may be shimmed or the inlet tube may be bent. However, even if the inlet tube and the reactor tube are coaxially aligned when the reactor is cool, misalignment often reoccurs when the reactor is heated, since the high temperatures cause structural elements of the reactor to warp or expand at different rates.
An additional problem with the reactor of the '545 patent relates to its inability to effectively compensate for undesirable operating conditions while the reactor is operating. Even if the inlet tube is axially aligned with the reactor tube, the reactor operation is affected by numerous operational variances, e.g., the feedstock input rate and material, the gas injection rate, the uniformity of the fluid wall, and the output from each of the heating elements. Fluctuations in these operational variances may cause undesirable operating conditions which may be minimized or corrected by techniques which involve the termination of the reactor operation, the correction for the undesirable condition, and the subsequent commencement of the reactor operation. Those skilled in the art recognize that such "shut down" and "start up" operations are expensive, time consuming, and contribute to reduced life for many reactor components.
The disadvantages of the prior art are overcome by the present invention, and an improved reactor feed tube mounting assembly is hereinafter disclosed which is pivotably adjustable with respect to the reactor tube. Also disclosed is an improved method of effectively increasing reactor operational time by pivotally adjusting of the feed tube relative to the reactor to compensate for or correct undesirable reactor operating conditions.